Field
The present disclosure relates to radio frequency (RF) signal processing. RF systems rely on an ability to isolate a desired received signal amongst energy generated by hundreds of sources. It is the job of the receiver to detect a signal of interest while rejecting all others. Modern RF circuits can tolerate blockers (blocking or interfering signals) when they are sufficiently out of the frequency band of the signal of interest, by using filters. A bandpass filter at the front end of a receiver (e.g., superheterodyne, direct down conversion or low intermediate-frequency (IF) receiver) can mitigate the out of band blockers. For signals adjacent to the target band however, the filter will not sufficiently diminish the interference. Due to spectrum congestion, it is now possible for a blocker to be sufficiently close in frequency and space to overload the receiver and decrease the signal-to-noise ratio. In other words, the ability to receive a desired signal is greatly limited when there is a strong near-band interfering signal. A signal that occupies the adjacent band of a desired signal is called co-channel, and the act of hindering reception of such desired signal is called co-channel interference, or CCI.
Description of the Related Art
Amplifier devices can be used in processing radio frequency signals. Certain amplifier devices can generate undesirable distortion, which may affect system performance.